Hi,

     Please find my Modified method here. Please make a try and let us know the reult. However it is not tested.

        public string[] GetClientName(string prefixText, int count, ref string strErrorMessage)
        {
            strErrorMessage = "";
            try
            {
                objBMAutoComplete.SearchString = prefixText;
                objBMAutoComplete.RequestFrom = "CL";
                objBMAutoComplete.SearchFor = "NAME";

                DataSet dataSet = objBMAutoCompleteManager.GetINCAutoSearchData(objBMAutoComplete);
                List<string> items = new List<string>(dataSet.Tables[0].Rows.Count);

                if (dataSet.Tables[0] != null)
                {
                    for (int i = 0; i <= dataSet.Tables[0].Rows.Count - 1; i++)
                    {
                        if (!items.Contains(dataSet.Tables[0].Rows[i]["DisplayName"].ToString().Trim()))
                            items.Add(dataSet.Tables[0].Rows[i]["DisplayName"].ToString().Trim());
                    }
                }
                return items.ToArray();
            }
            catch (SoapException ex)
            {
                strErrorMessage = ex.Message;
                return null;
            }
        }